* {
    margin: 0;
}

ol,
li {
    list-style: none;
}

.main {
    position: relative;
}

.tool {
    display: inline-block;
    position: absolute;
    top: 0;
    left: 0;
    cursor: pointer;
}

.tool svg {
    width: 3em;
    height: 3em;
    margin: 15px 15px 0;
    /* 过渡效果，延迟动画 */
    transition: all 0.3s;
}

.tool svg.active {
    fill: orange;
    transform: scale(1.3);
}

.colors {
    position: absolute;
    top: 100px;
    left: 10px;
    cursor: pointer;
}

.colors>li {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: 1px solid gray;
    margin: 10px -35px;
    transition: all 0.3s;
}

.colors>li.black {
    background: black;
}

.colors>li.red {
    background: red;
}

.colors>li.green {
    background: green;
}

.colors>li.blue {
    background: blue;
}

.colors>li.skyblue {
    background: skyblue;
}

.colors>li.orange {
    background: orange;
}

.colors>li.active {
    transform: scale(1.2);
}